Process for breaking petroleum emulsions



United States Patent PROCESS FOR BREAKING PETROLEUM EMULSIONS NoDrawing. Application April 10, 1952, Serial No. 281,645

14 Claims. (Cl. 252-341) This invention relates to processes orprocedures particularly adapted for preventing, breaking or resolvingemulsions of the water-in-oil type, and particularly petroleumemulsions.

Complementary to the above aspects of my invention is my companioninvention concerned with the new chemical products or compounds used asthe demulsifying agents in said aforementioned processes or procedures,as well as the application of such chemical compounds, products and thelike, in various other arts and industries, along with the method formanufacturing said new chemical products or compounds which are ofoutstanding value in demulsification. See my co-pending application,Serial No. 281,646, filed April 10, 1952.

My invention provides an economical and rapid process for resolvingpetroleum emulsions of the water-in-oil type, that are commonly referredto as cut oil, roily oil, emulsified oil, etc., and which comprise finedroplets of naturally-occurring waters or brines dispersed in a more orless permanent state throughout the oil which constitutes the continuousphase of the emulsion.

It also provides an economical and rapid process for separatingemulsions which have been prepared under controlled conditions frommineral oil, such as crude oil and relatively soft waters or weakbrines. Controlled emulsification and subsequent demulsification underthe conditions just mentioned are of significant value in removingimpurities, particularly inorganic salts, from pipeline oil.

Demulsification as contemplated in the present application includes thepreventive step of commingling the demulsifier with the aqueouscomponent which would or might subsequently become either phase of theemulsion in the absence of such precautionary measure. Similarly, suchdemulsifier may be mixed with the hydrocarbon component.

Briefly stated, the present invention in one of its more importantaspects is concerned with the resolution of water-in-oil emulsions bymeans of certain fractional esters hereinafter described in detail.

In practicing the process of the present invention one may employcompounds derived from either polyamines in which the nitrogen atoms areseparated by an ethylene radical or by a propylene radical or by atrimethylene radical. Reference to a propylene radical means a methylsubstituted ethylene radical, i. e., having only 2 carbon atoms betweennitrogen atoms. From a practical standpoint as will be explainedhereinafter, the polyethylene imidazolines are most readily availableand most economical for use. Thus, broadly speaking, the presentinvention is concerned with a process for breaking petroleum emulsionsof the water-in-oil type characterized by subjecting the emulsion to theaction of a demulsifier including synthetic hydrophile products; saidsynthetic hydrophile products being obtained by reaction between (A) apolycarboxy acid, and (B) a highly oxypropylated substituted ringcompound consisting of in which R is a divalent alkylene radicalselected from the class consisting of and in which D represents adivalent, non-amino, organic radical containing less than 25 carbonatoms, composed of elements from the group consisting of C, H, O, and N;Y represents a divalent, organic radical containing less than 25 carbonatoms, composed of elements from the group consisting of C, H, O, and N,and containing at least one amino group, and R is a member of the classconsisting of hydrogen, aliphatic hydrocarbon radicals, hydroxylatedaliphatic hydrocarbon radicals, cycloaliphatic hydrocarbon radicals, andhydroxylated cycloaliphatic hydrocarbon radicals; R" is a member of theclass consisting of hydrogen, aliphatic radicals and cycloaliphaticradicals, with the proviso that in the occurrence of the radicals R andR" there be present at least one group of 8 to 32 uninterrupted carbonatoms; and with the further proviso that (1) there be introduced atleast 12 moles of propylene oxide per substituted nitrogen-containingring compound, and that (2) there be employed at least one mole of thepolycarboxy reactant for each reactive hydroxyl radical.

More specifically, and in a more limited scope, the present invention isconcerned with a process for breaking petroleum emulsions of thewater-in-oil type characterized by subjecting the emulsion to the actionof a demulsifier including hydrophile synthetic products; saidhydrophile synthetic products being obtained by reaction between (A) apolycarboxy acid, and (B) a highly oxypropylated substituted imidazolineconsisting of in which D represents a divalent, non-amino, organicradical containing less than 25 carbon atoms, composed of elements fromthe group consisting of C, H, O, and N; Y represents a divalent, organicradical containing less than 25 carbon atoms, composed of elements fromthe group consisting of C, H, O, and N, and containing at least oneamino group, and R is a member of the class consisting of hydrogen,aliphatic hydrocarbon radicals, hydroxylated aliphatic hydrocarbonradicals, cycloaliphatic hydrocarbon radicals, and hydroxylatedcycloaliphatic hydrocarbon radicals; R" is a member of the classconsisting of hydrogen, aliphatic radicals and cycloaliphatic radicals,with the proviso that in the occurrence of the radicals R and there bepresent at least one group of 8 to 32 uninterrupted carbon atoms;

actant for each reactive hydroxyi radical.

Generally speaking, as explained hereinafter, almost invariably therewill be employed one mole of polycarboxy reactant for each hydroxylradical. More can be In some instances, however, one can use modestlyless than one mole of the polycarboXy reactant for each reactivehydroxyl radical without in any way changing the nature of the instantinvention, provided only there is no difiiculty from cross-linking,gelation, formation of rubberlike compounds, etc. In other words, ifgels are formed the amount of polycarboxy reactant should be increased.If no gel is formed a somewhat reduced amount can be employed, providedthat rubberlike character does not enter.

As pointed out elsewhere, R in the preceding formulas, when derived froma hydroxy fatty acid, such as ricinoleic acid, actually contains theelement oxygen in addition to the hydrocarbon group without detractingfrom the hydrophobe character transmitted by the hydrocarbon group andyet makes the radical susceptible to oxyproplylation.

These materials can be obtained in any suitable manner. They can eitherbe purchased in the open market or the substituted imidazolines can beprepared as described in U. S. Patent Re. 23,227, dated May 9, 1950, toBlair and Gross. The most readily available sources of polyamines arepolyethylene polyamines having from 2 to 7 or 8 nitrogen atoms. The mostreadily available source of the hydrocarbon radical which becomessubstituted in imidazoline ring is a detergent-forming monocarboxy acidhaving approximately 8 to 32 carbon atoms as exemplified by fatty acids,resin acids such as abietic acid, napththenic acid, or the like. Suchdetergent-forming monocarboxy acids have been described in theliterature and are characteristic of the fact that they combine with thewatersoluble base, such as caustic soda, caustic potash, or ammonia, togive detergent or detergent-like compounds. The most suitable alkaleneoxide to use is propylene oxide.

Indeed, for all practical purposes, the derivatives obtained frompropylene oxide are so markedly superior to other alkylene oxides, forinstance, even nearby oxides such as ethylene oxide and the variousbutylene oxides, that such other oxides can be ignored in this inventionand it be considered as limited specifically to propylene oxide. As

pointed out elsewhere, without detracting from the spirit of theinvention one could employ a small percentage of ethylene oxide orbutylene oxide along with the propylene oxide provided it did not affectthe inherent character of the compound. The preparation of substitutedimidazoline is well known and requires no discussion. The oxy alkylationof substituted imidazolines is well known. See, for example, U. S.Patent No. 2,211,011, dated August 13, 1940, to Chwala, and U. S. PatentNo. 2,468,180, dated April 26, 194-9, to De Groote and Keiser. It is tobe noted that the above patents are concerned with oxyalkylation broadlyand are not limited to oxyalkylation, and to the extent thatoxypropylation is employed the degree is modest and not within thedescription or characterization of excessive oxypropylation as hereinincluded as part of the invention.

What has been said in the preceding paragraph may be explained furtherin the following manner. If a watersoluble substance, such as wateritself, is treated with ethylene oxide the resultant or mixture ofcompounds so obtained continues to be water-soluble to a high molecularweight range, for instance, 2,000. If, on the other hand, propyleneoxide is used instead of ethylene oxide, then and in that event whenapproximately 12 moles or more of propylene oxide are introduced perhydrophile unit water-insolubility results. For example, compare thewater-insolubility of polypropylene glycol having twice this molecularweight. As far as I am aware there is no previous reference to highlyoxypropylated substituted imidazolines, i. e., the introduction of atleast 12 and preferably more than 12 moles of propylene oxide persubstituted imidazoline molecule.

The amount of propylene oxide used need not be limited to being justmoderately in excess of 12 molesof propylene oxide per imidazolinemolecule. In a general way, I prefer to use approximately 6 to 10 molesof propylene oxide per nitrogen atom in the original 'polyalkylene amineand, more specifically, the polyethylene amine employed as a reactant.In such instances where the substituted imidazoline is derived from ahydroxylated fatty derivative as described elsewhere, even largeramounts of propylene oxide are not only acceptable but may even bedesirable.

Having obtained the oxypropylated substituted imidazoline hereinafterdescribed in detail, the next step is esterification involving apolycarboxy acid, and preferably a dicarboxy acid or reactant, in suchmolal ratio as to insure'the presence of esterified carboxyl radicals.As a matter of fact, I have found it preferable to use at least one moleof the polycarboxy reactant for each hydroxyl raical present, but notnecessarily limited as stated elsewhere.

For convenience, what is said hereinafter will be divided into fiveparts:

Part 1 is concerned with the selection or preparation of the substitutedimidazoline;

Part 2 is concerned with the oxypropylation of the imidazoline asdescribed in Part 1 preceding;

Part 3 is concerned with the formation of the acidic ester from theoxypropylated imidazoline described in Part 2, preceding; 1

Part 4 is concerned with the nature of the oxypropylated derivativesinsofar that a cogeneric mixture is invariably obtained; and

Part 5 is concerned with the process for breaking oil field emulsions,or similar emulsions, by means of the acidic esters as described in Part3, preceding.

PART 1 bean oil, naphthenic acids of various molecular weights varyingfrom 200 to 250 up to approximately 400, abietic acid, talloil'representing a mixture of resin aicds and unsaturated fatty acids,etc. The mixed fatty acids obtained from the saponification 'of linseedoil are particularly suitable. The polyamines most readily available arepolyethylene amines having 2 to 6, 7 or 8 nitrogen atoms. My preferredpolyamines contain 3, 4 or 5 nitrogen atoms. Propylene oxide, of course,is readily available.

Oxypropylation is most readily accomplished by virtue of labile hydrogenatoms as part of the imidazoline ring.

This means the presence of one or more hydrogen atoms attached tonitrogen or attached to oxygen, or both.

However, it is possible to prepare an oxypropylated derivative from animidazoline in which there is no labile hydrogen atom present as part ofthe imidazoline radical. For instance, if one prepares a compound of thefollowing formula:

in which both R and X represent high molal groups, then obviouslyoxypropylation must involve the group R, assuming that X is notsusceptible to oxypropylation, and B is selected from the classconsisting of hydrogen atoms and methyl groups, with the proviso thatthe methyl group occurs not more than once. One can prepare aromaticfatty acids from materials such as phenol and an unsaturated acid suchas oleic acid by means of aluminum chloride or sulfuric acid. Itsulfuric acid is employed the compound can be desulfonated. In anyevent, one obtains a modified fatty acid which contains a reactivehydrogen atom, to wit, one attached to the phenolic radical. Similarly,hydroxylated fatty acids, such as ricinoleic acid,

hydroxyacetic acid, etc., can be oxypropylated, provided the reactioncannot take place preferentially at some other point in the molecule as,for example, even an ester linkage. Thus, such compound or compoundsresulting from the introduction of a hydroxyethyl group provides amodified detergent-forming acid or its obvious equivalent which, for theherein described purpose, is just as satisfactory as the unmodifiedfatty acid or equivalent. Similar changes can be made in resin acids andnaphthenic acids. However, there is no justification for selecting suchexpensive reactant and apparently no added benefit is obtained. For thisreason I prefer to use a polyamine as a reactant in which thesubstituted imidazoline contains a plurality of reactive hydrogen atoms.In any event, the substituted imidazoline must beoxyproplyationsusceptible or it is not contemplated as a reactant forthe instant purpose.

Compounds which I have found to be effective for the purpose describedbelong to the general class of cyclic amidines, and in particular aresubstituted imidazolines, in which the imidazoline molecule contains atleast one aliphatic, or cyloaliphatic hydrocarbon group containing from8 to 32 carbon atoms. Cyclic imidazolines in which the 2-carbon atom issubstituted by a long chain aliphatic hydrocarbon group are particularlyeasy to prepare and are very effective for the present use.

Shown in the most general way, as far as the S-membered ring derivativesare concerned, the compounds contemplated for use in oxypropylationherein may be represented by the following formula:

where n is the numeral 1 to 6 and R is hydrogen or an aliphatic orcycloaliphatic hydrocarbon radical.

In the simplest case, the group R may be directly attached to thel-nitrogen atom of the ring, as follows:

I have found that particularly outstanding demulsifiers result when theparent imidazoline compound contains basic nitrogen groups in additionto those inherently 6 present in the imidazoline ring. In general,compounds of this type which are effective are those in which the basicnitrogen group is contained in the radical D in the above formula.

In this case the products may be represented by the formula:

where R and R are hydrogen or a hydrocarbon radical, and in which atleast one of the groups R and R is an aliphatic or cycloaliphatichydrocarbon group containing from 8 to 32 carbon atoms; Y is a divalentorganic radical containing amino groups, and B is selected from theclass consisting of hydrogen atoms and methyl groups, with the provisothat the methyl group occurs not more than once. The group R may be, andusually is, an amino nitrogen substituent. Examples of organic radicalswhich YR may represent are:

CH2 CH2 where R and R have their previous significance.

Of this class of reagents in which an amino group occurs as a portion ofthe l-nitrogen substituent, those which are derived, at leasttheoretically, from the polyethylene polyamines appear to beparticularly effective as demulsifiers and are so outstanding as toconstitute an invention Within an invention. These have the generalformula:

Where R and R have their previous meanings, in is a small number,usually less than 6, and B is selected from the class consisting ofhydrogen atoms and methyl groups, with the proviso that the methyl groupoccurs not more then once.

The preparation of an imidazoline substituted in the 2-position byaliphatic hydrocarbon radicals is well described in the literature andis readily carried out by reac tion between a mono-carboxylic acid and adiamine, or

' polyamine, containing at least one primary amino group,

and at least one secondary amino group, or another primary amino groupseparated from the first primary amino group by two carbon atoms.Examples of suitable polyamines which can be employed for thisconventional imidazoline synthesis include ethylenediamine,diethylenetriamine, triethylenetetramine, tetraethylenepentamine,1,2-diaminopropane, N-ethyl-ethylenediamine,N,N-dibutyldiethylenetriamine, 1,2-diaminobutane,hydroXyethylethylenediamine, dipropylenetriamine and the like. Fordetails of the preparation of these reagents see radicals, or anotherimidazoline group, an aliphatic or cycloaliphatic hydrocarbon radicalhaving the following U. S. Patents: U. S. No. 1,999,989, dated April 30,193 5, Max Bockmuhl et ah; U. S No. 2,155,877, dated April :25, l939,Edmund Waldmann et al.; and U. S. No. 2,155,878, dated April 25, 1939,Edmund Waldinann et al. Also see Chem. Rev., 32, 47 (43).

Attention is directed to the fact that the hydrocarbon radicalseparating the nitrogen atoms may have as many as 4 carbon atoms, ormore, provided that the chain is branched and the actual number ofcarbon atoms between the nitrogen atoms is not more than 3. This isillustrated by secondary butylene diamine, di-secondary butylenetriamine, tri-secondary butylene tetramine, etc. The structural forrnulof di-secondary butylene triamine is as follows:

When an aliphatic or cycloaliphatic carboxylic acid containing 9 or morecarbon atoms is employed in the above described synthesis, the resultingimidazoline will contain a 2-substituent consisting of an aliphatichydrocarbon radical containing 8 or more carbon atoms. Suitabledemulsifiers may, therefore, be made directly by reaction of acids suchas oleic acid, linoleic acid, linolenic acid, erucic acid, talloil fattyacids, naphthenic acids, nonoic acid, and the like, with suitable aminessuch as those enumerated above. When this condensation is carried out ata temperature of 250 C. or higher, between equal mole proportions ofmono-carboxylic acid and polyamine, two moles of water are evolved andthe desired imidazoline is formed in almost quantitative yield.

7 Such suitable reagents may be represented by the following formula:

where X may be ethylene amino radicals, aminoalkyl and where A is from 8to 32 carbon atoms. In the above formulas for imidazolines it should bepointed out that where X is a hydrogen atom, the nitrogen atoms becomeequivalent, insofar as reaction is concerned, and cannot bedistinguished from one another. This is supposed, on theoreticalgrounds, to result from the mobility of the hydrogen proton, and itsease of transfer from one nitrogen atom to the other. However, where Xis an organic substituent other than hydrogen, the nitrogen atoms are'nolonger equivalent. For the purpose of the present application, thenitrogen atom to which the radical X is attached will be called thel-nitrogen atom of the imidazoline ring. This is in conformance with theusual chemical convention in numbering heterocyclic ring positions.

Examples of suitable substituted imidazolines in which the aliphatic orcycloaliphatic group containing from 8 to 32 carbon atoms on either theoneor 2-position substituent, are exemplified as follows:

N-'CH2 CnHnO bil -CH2 H Z-undecylimidazoline /N-CH1 nBas- Al -CH2 HZ-heptadeeylirnidazoline NC H'2 C'BHI'I IIF-G H2 C 2H4 O H 2-octyl,1-hydroxyethylimidztzoline N-@ 112 O H 0 H2 0 C H2 C 1H4 O C 12Hl-dodecyloxyethyl, 2-hydroxymethyl imidazoline N-CH2 C 21150 lTT- C H2CzHrNHC 10H 1 N-decylamin oethyl, 2-ethylirnidazoline N-CHi C ITHZ-S- C}\I-G H2 H 2-o1ey1imidazolinc mercially available polyethylenepolyamines, or from polyamines in which there are three or more aminogroups and in which there is at least one primary amino group separatedby two carbon atoms from a secondary or primary amino group. Examples ofsuitable preferred compounds of this type are the following:

N-CH2 4,2-di-rnethy1, LhexadecylaminoethylaminoethylimidazolineJaHs.NH.C12H2a l-doderylaminopropylimidazoline1-stearoyloxyethylaminoethylimidazolin'e H .N.C:H4OH

JnHM 2-ethy1. 1- (N,N dodecyl, hydroxyethyl aminoethylimidazoline N CH2H.C

2H .NH. C 2H4NHO C C 171135 l-stearamidoethylaminoethylimid azoline N CH2 2H4.N. O2H4.NH 0 0.0213

1- (N-dodecyl acetamidoethylaminoethylimidazoline NC H2 C H3. 0

N-O H2 tmNnczsrniols Chloroparafiin alkylatlon product of l-aminoethyl,Z-rnethylimidazoline 4-methy1,2dodecyl,l-aminoethylarninoethyltetrahydropyrimidine It is unnecessary to point out that when polyamineshave 4 or more nitrogen atoms one can prepare a compound having 2imidazoline rings. This may be illustrated by a compound of thefollowing formula:

Such compounds can be derived, of course, from triethylenetetramine,tetraethylenepentamine, pentaethylenehexamine, and higher homologues.The substituents may vary depending on the source of the hydrocarbonradical, such as the lower fatty acids and higher fatty acids, a resinacid, naphthenic acid, or the like. The group introduced may or may notcontain a hydroxyl radical as in the case of hydroxyacetic acid, aceticacid, ricinoleic acid, oleic acid, etc.

I have found no advantage in preparing such compounds containing 2imidazoline rings and, as a matter of fact, prefer to prepare thesimpler compounds having only one imidazoline ring. However, it ispossible that in the preparation of compounds herein described intendedto have only one imidazoline ring there is some of the compound :formedhaving 2 such rings. It is understood, however,

19 that a compound having 2 such rings is the obvious chemicalequivalent of the simple compound and is herein contemplated as part ofthe present invention.

Such diimidazolines are intended to be included When reference is madeto substituted imidazolines herein or in the claims.

PART 2 Previous reference has been made to the formation of an ester byreaction between a polycarboxy reactant and the products obtained byoxypropylation. Actually, this is an over-simplification for reasonswhich are obvious on closer examination. If, for example, one employs atetramine, pentamine, hexamine, or the like, and reacts with a highmolal monocarboxy acid to form a substituted imidazoline, the resultantproduct may have as a residue 1, 2, 3 or more amino hydrogen atoms whichare susceptible to oxypropylation. It is entirely satisfactory andpreferred that oxypropylation be so conducted that all amino hydrogenatoms react with propylene oxide. This may not be possible. The reasonfor this statement is that the oxypropylation is comparable to theoxypropylation of the parent body, i. e., the polyamine. Examination ofoxypropylated polyamines, for instance, tetraethylene pentamine,suggests that there is no uniform propylation at all points of reactionthroughout the procedure regardless of the conditions of oxypropylation.There is every reason to believe that in the case of comparablecompounds, i. e., the substituted imidazolines herein employed as rawmaterials, the same situation prevails. This has an obvious significanceinsofar that one cannot predict with certainty whether or not, if therebe any residual non-oxypropylated amino group present, such group inturn would be reactive towards the polycarboxy reactant to form anamide. Evidence seems to be that in some instances amides are formed butnot necessarily in all instances where nonoxypropylated amino groups arepresent. For this reason where previous reference has been made to anester it is true that an ester group is invariably present due to thedecrease in the hydroxyl number after esterification but one cannot ruleout the possibility of the formation of amides under appropriatecircumstances where the reactants permit such formation.

Over and above this another factor must be considered and that is this.The substituted imidazoline ring invariably contains one broadly basicnitrogen atom. The oxypropylated nitrogen groups also may be fairlybasic, at least modestly so. For this reason when a polycarboxy reactantis employed within the range previously specified and in the mannerdescribed in greater detail in Part 3 immediately succeeding there isthe distinct possibility that a salt-like structure may be set upinvolving any free hydroxyl radical. The salt-like structure may involvea multiplicity of molecules or a single molecule. No data are availablein regard to this particular point although it has been subjected tocareful examination. It is to be noted, however, that nothing that issaid herein, in the slightest way detracts from the ability to producethe described reactants without any difliculty whatsoever and suchreactants, notwithstanding certain minor variations which are possible,are all uniformly satisfactory for the herein described purpose. It isto be noted also that this does not detract in any way from the abilityto point out this invention with specificity.

Amplifying what has been said previously it may be worthwhile toconsider what happens in the case of the oxypropylation of higherpolyamines because the structural elements are similar for reasonsspecified. As stated, there is evidence that all the available hydrogenatoms are not necessarily attacked, at least under modest oxypropylationconditions and particularly when oxypropylation proceeds atcomparatively low temperatures as herein described, for example,somewhere between the basic nitrogen atoms present.

l quite possible that three long propylene oxide chains are built upbefore the two remaining hydrogens are attacked and perhaps not attackedat all. This, of course, depends on the conditions of oxypropylation.However, analytical procedure is not entirely satisfactory in someinstances in difierentiating between a reactive hydrogen atom attachedto nitrogen and a reactive hydrogen atom attached to oxygen.

In the case of triethylenetetramine the same situation seems to follow.One hydrogen atom on the two terminal groups is first attacked and thenthe two hydrogen atoms on the two intermediate nitrogen atoms. Thus,four chains tend to build up and perhaps finally, if at all, theremaining two hydrogen atoms attached to the two terminal groups areattacked. In the case of tetraethylenepentamine the same approach seemsto hold. One hydrogen atom on each of the terminal groups is attackedfirst, then the three hydrogen atoms attached to the three intermediatenitrogen atoms, and then finally, if at all,

depending on conditions of oxypropylation, the two remaining terminalhydrogen atoms are attacked.

If this is the case it is purely a matter of speculation at the momentbecause apparently there is no data which determines the mattercompletely under all conditions of manufacture, and one has a situationsomewhat comparable to the acylation of monoethanolamine ordiethanolamine, i. e., acylation can take place involving either thehydrogen atom attached to oxygen or the hydrogen atom attached tonitrogen. Oxypropylation of the nitrogen compounds to produce 5.

intermediates used for the production of the products used in accordancewith the present invention is carried out in the usual type of equipmentfor oxyalkylations and by the procedures commonly used for theoxyalkylation of compositions having labile hydrogen atoms. For adiscussion of the factors involved see, for example, United StatesPatent 2,679,513, Part 1 in columns 6, 7, 8, 9 and 10. This procedurewill be illustrated by Examples 1a through 24a herein.

It is to be noted that in the present instance one has These basicnitrogen atoms will themselves catalyze the oxypropylation reaction forat least a little while. For this reason the use of an alkaline catalystmay be omitted in the beginning.

However, it is obvious that as oxypropylation proceeds the nitrogenatoms will decrease in basicity and the reaction must slow down. Then itbecomes necessary to add an alkaline'catalyst, such as caustic potash orcaustic soda, to continue the reaction. However, there is no apparentadvantage to delaying the addition of the alkaline catalyst. For thisreason I prefer to add an alkaline catalyst at the very beginning andcontinue the reaction through without a break. In most instances 1% tocatalyst by weight of imidazoline will suffice.

As mentioned elsewhere the imidazolines range from water-dispersible tooil-soluble, i. e., kerosene or xylenesoluble, as oxypropylationproceeds. As a matter of fact, I have found it preferable to employthose oxypropylation products which are oil-soluble, that is, the bulkof whose cogeneric mixtures are oil-soluble. These oil-solubleoxypropylation derivatives are represented, broadly speaking, by thoseimidazoline products having 20 or more moles of propylene oxide per moleof imidazoline product.

Example 1a The particular autoclave used was one with a capacity ofapproximately 15 gallons or on the average of about pounds of reactionmass. The speed of the stirrer could be varied from to 350 R. P. M. Theinitial charge was 66.9 pounds of a castor oil triethylenetetramineimidazoline product taken from a batch made by reacting 53.5 parts ofcastor oil with 24.1 parts of triethylenetetramine. 1.33 pounds ofcaustic were added as a catalyst. The reaction pot was flushed out withnitrogen, the autoclave sealed, and the automatic devices adjusted andset for injecting 48.7 pounds of propylene oxide in a 10-hour period.The pressure regulator was set for a maximum of 3537 pounds per squareinch. However, in this particular step. and in all succeeding steps thepressure never got over about 32 pounds per square inch. In fact, thismeant that the bulk of the reaction could take place and did take placeat an appreciably lower pressure. This comparatively low pressure wasthe result of the fact that the reactant per so was basic. The propyleneoxide was added at a rate of about 10 pounds per hour and at acomparatively moderate temperature, to wit, about 250255 F. (moderatelyhigher than the boiling point of water). The initial introduction ofpropylene oxide did not start until the heating devices had raised thetemperature to 245 F. At the completion of the reaction a sample wastaken and oxypropylation proceeded as in Example 2a immediatelyfollowing.

Example 2a of propylene oxide introduced the time period was muchshorter, to wit, 3 hours. The rate of oxide introduction was about 15 to16 pounds per hour. At the end of the reaction period part of the samplewas withdrawn and oxypropylation continued as in Example 3a, immediatelyfollowing. 7

Example 3a 81.43 pounds of the reaction mass identified as Example 2a,preceding, and equivalent to 35.8 pounds of imidazoline, 44.8 pounds ofpropylene oxide, and 0.71 pound of catalyst, were permitted to stay inthe auto clave. 20.4 pounds of propylene oxide were introduced in a5-hour period. No additional catalyst was added.

The conditions of reaction as far as temperature and pressure wereconcerned were substantially the same as in Example In, preceding. Thepropylene oxide was added at the rate of about 5 /1 pounds per hour. Atthe completion of the reaction part of the reaction mass was withdrawnand the remainder subjected to further oxypropylation as described inExample 40, immediately following.

Example 4a 76.83 pounds of the reaction mass identified as Example 3a,preceding, and equivalent to 27.1 pounds of imidazoline, 49.4 pounds ofpropylene oxide, and 0.54 pound of catalyst were permitted to stay inthe autoclave. No additional catalyst was added.

The conditions in regard to temperature and pressure were substantiallythe same as in Example 1a,'preceding. In this instance the oxide wasadded in 7 hours. The amount of oxide added was 21 pounds. The additionwas at the rate of about 7 pounds per hour.

What has been said herein is presented in tabular form in Table 1immediately following with some added in-. formation as to theoreticalmolecular weight, hydroxyl number, etc. Also, other examples have beenpresented in this table as it is not necessary to cite them all indetail as has been done with the preceding ex-' amples.

TABLE 1 Oxide, Catalyst, Imidazo., Oxide, Catalyst, Wt.

s. l s. l s. s. s.

zoline product derived from ricinoleic acid and Duomeen T. the followingformula: RNHCH2CH2CH2NH2, where R consists of C iznidazoline will beoiwalkylation-susceptible only in the radical on the 2- iniormation isaccording to the manufacturer, Armour Chemical Oompa Max Max Time Temp,pres F. p. s. i g

(Duomeen T is a product of approximately re and 01s hydrocarbon chains.Note that this carb)on position, 1. e., the ricinoleic radical. Thislmidazoline product derived from oleic acid and trimethylenediamine.Note that this will produce a G-membered imidazoline ring.

The product at the end of the oxypropylation step, was a somewhatviscous amber to dark-reddish colored fluid. In general the colorgradually lightens as oxypropylation proceeds. The hydroxyl valuesmentioned in the above table immediately preceding were determined bythe standard Verley-Bolsing method. This value is sometimes referred toas acetyl value and is a well known determination in the art. It is tobe noted that there is no complete conversion of propylene oxide intothe desired hydroxylated compounds. This is indicated by the fact thatthe theoretical molecular weight based on a statistical average isgreater than the molecular weight when calculated on the basis of acetylor hydroxyl value. Actually, there is no completely satisfactory methodfor determining the molecular weights of these types of compounds with ahigh degree of accuracy. In some instances the acetyl value or hydroxylvalue serves as satisfactorily as an index to the molecular weight asany other procedure molecular weight range. in the manufacture of theesters as described in Part 3, succeeding, a stoichiometrical amount ofacid or acid compound should be taken which corresponds to the indicatedacetyl or hydroxyl value. This matter has been discussed in theliterature and is a matter of common knowledge and requires no furtherelaboration.

In the above table the time factors mentioned are generally longer thanwould ordinarily be required. Needless to say, the oxypropylation ratecan be speeded by increasing the agitation or the temperature and by achoice of suitable reaction vessels. However, as it is sometimesdesirable to allow the reaction mass to stir for as long as a half-hourto one hour before drawing a sample PART 3 As pointed out previously thepresent invention is concerned with compounds or derivatives involvingester linkages obtained from the oxypropylated derivatives described inPart 2 immediately preceding, and polycarboxy acids, particularlytricarboxy acids like citric acid.

and dicarboxy acids such as adipic acid, phthalic acid, or anhydride,succinic acid, diglycolic acid, sebacic acid, azelaic acid, aconiticacid, maleic acid or anhydride, citraconic acid or anhydride, maleicacid or anhydride adducts as obtained by the Diels-Alder reaction fromproducts such as maleic anhydride and cyclopentadiene. Such acids shouldbe heat stable so they are not decomposed during esterification. Theymay contain as many as 36 carbon atoms as, for example, the acidsobtained by dimerization of unsaturated fatty acids, unsaturatedmonocarboxy fatty acids, or unsaturated monocarboxy acids having 18carbon atoms. Reference to the acid in the hereto appended claimsobviously includes the anhydrides or any other obvious equivalents. Mypreference, however, is to use polycarboxy acids having not over 8carbon atoms.

The production of esters including acid esters (fractional esters) frompolycarboxy acids and polyols or other hydroxylated compounds is wellknown. In this case the hydroxylated compounds obtained as described inPart 2, preceding, contain nitrogen atoms which are Keiser, andparticularly with apt to be basic. Thus, as has been explainedpreviously, it is probable, particularly where there is a basic nitrogenatom present, that salts may be formed but in any event under theconditions described it is improbable, in fact almost impossible, forthe reaction to take place without the formation of ester linkages. Ithas been pointed out, also, that under some of the circumstances atleast, amidification may enter into the reaction. Over and above this isthe fact that the radical previously indicated as R, i. e., the radicalattached to the 2-position carbon atom of the ring, may include in itsstructure a hydroxyl group as in such instances where it is derived fromricinoleic acid, hydroxystearic acid, etc. Thus, it becomes obvious thateven if a dicarboxy acid or anhydride is employed there may be present 3or more points of reaction in the other material employed in theesterification reaction, i. e., the oxypropylated derivative. For thisreason there is also the possibility, unless appropriate precautions aretaken, that insoluble resins or gelatinous materials will be formed. Ihave found that this can be avoided by adding suflicient low molalsulfonic acid, such as paratoluene sulfonic acid, or even hydrochloricacid, to neutralize the basicity prior to esteriflcation. The additionof such acid'catalyst, of course, serves another purpose-to eliminateany basic catalyst which was left from the oxypropylation procedure.Needless to say, addition of the strong acid provides the conventionalrole of esterification catalyst which is desirable in the instant casealthough not absolutely essential in such case. The same situation hasbeen noted in comparable reactions, for instance, esterification oftriethanolamine or polymerized derivatives of triethanolamine. It means,perhaps, that in the instant case the compounds employed in the processfor breaking petroleum emulsions contain in part the salt form ofhydrochloric acid or paratoluene sultonic acid, or whatever acid may beemployed in this particular procedure. In any event, this is. merely amatter of detail and comparable processes and do not affect the stepherein referred to as the esterification procedure, although, as

pointed out, in at least a number of instances it is more complicatedthan simple esterification.

Needless to say, various compounds of the polycarboxy acids may be usedinstead of the free acid, such as the low molal ester, the anhydride,the acyl chloride, etc. However, for purpose of economy it is customaryto use either the acid or the anhydride. A conventional pro cedure isemployed. On a laboratory scale one can employ a resin pot of the kinddescribed in U. S. Patent No. 2,499,370, dated March 7, 1950, to DeGroote and one more opening to permit the use of a porous spreader ifhydrochloric acid gas is to be used as a catalyst. Such device orabsorption spreader consists of minute Alundurn thimbles which areconnected to a glass tube. One can add a sulfonic acid such asparatoluene sulfonic acid as a catalyst. There is some objection to thisbecause in some instances there is some evidence that this acid catalysttends to decompose or rearrange heat-oxypropylated compounds, andparticularly likely to do so if the esterilication temperature is toohigh. Generally, care is taken to add just a very slight excess of acidfor the actual esterification. The use of hydrochloric acid gas has oneadvantage over paratoluene sulionic acid and that is that at the end ofthe reaction it can be mostly removed by flushing out with nitrogen,whereas there is no reasonably convenient means available of removingthe paratoluene sulfonic acid or other sulfonic acid employed. Ifhydrochloric acid is employed one need only pass the gas through at anexceedingly slow rate so as to keep the reaction mass acidic. Only atrace of acid need be present. i have employed hydrochloric acid gas orthe'aqueous acid itself.

The products obtained in Part 2 preceding almost always contain a basiccatalyst. As a general procedure such procedures are well known in Isequently except by vacuum I have added an amount of half-concentratedhydrochloric acid considerably in excess of what .is required toneutralize the residual catalyst. The mixture is shaken thoroughly withxylene and allowed to stand overnight. It is then filtered and refluxedwith the xylene present until the water can be separated in aphase-separating trap. As soon as the product is substantially free fromwater the distillation stops. This preliminary step can be carried outin the flask to be used for esterific'ation. if there is any furtherdeposition of sodium chloride during the reflux stage needless to say asecond filtration may be required. In any event the neutral or slightlyacidic solution of the oxypropylated derivatives described in Part 2 isthen diluted further with sufllcient xylene, decalin, petroleum solvent,or the like, so that one has obtained approximately a 40% solution, Tothis solution there is added a polycarboxylated reactant as previouslydescribed, such as phthalic anhydride, succinic acid or anhydride,diglycollic acid, etc. The mixture is refluxed until esterification iscomplete as indicated by elimination of water or drop in carboxyl value.Needless to say, if one produces a half-ester from an anhydride such aspht-halic anhydride, no Water is eliminated. However, if it is obtainedfrom diglycollic acid, for example, Water is eliminated. Ordinarily thisrefluxing temperature is apt to be in the neighborhood of 160 C. topossibly 199 C. All such procedures are conventional and have been sothoroughly described in the literature that further consideration willbe limited to a few examples and a comprehensive table.

The above mentioned petroleum solvents are sold by various oilrefineries and, as far as solvent effect, act as if they were almostcompletely aromatic in character. Typical distillation data in theparticular type I have employed and found very satisfactory is thefollowing:

i. 5.1 142 C. 50 ml., 242 C. 5 mL, 200 C. ml. 244" C. 10 ml., 209 C.ml., 248 C.

15 ml., 215 C. 20 ml., 216 C.

1111., 252 C. ml., 252 C.

The addition of such high-boiling solvent or solvents in conjunctionwith xylene provides a very flexible system for controlling theesterification temperature. Obviously, the more xylene present the lowerwill be the refluxing temperature and, conversely, the more high boilingsolvent present the higher will be the refluxing temperature. Normally,I prefer to start refluxing at as low a temperature as possible, i. e.,with much xylene present, but if the esterification reaction does notseem to be proceeding satisfactorily then 'I merely Withdraw more andmore solvent mixture from the reflux trap thereby raising thetemperature. As mentioned, by using this method the esterificationtemperature can be ranged easily from to possibly C. My preference isnot to go over 200 C. under any circumstances.

The use of such solvent is extremely satisfactory pro.- vided one doesnot attempt to remove the solvent subdistillation and provided there isno objection to a little residue. Actually, when these materials areused for a. purpose such as demulsification the solvent might just aswell be allowed to remain. If the solvent is to be removed bydistillation, and particularly vacuum distillation, then the highboiling aromatic petroleum solvent might well be replaced by some moreexpensive solvent, such as decalin or an alkyll J ated decalin which hasa rather definite or close range boiling point. The removal of thesolvent, of course, is purely a conventional procedure and requires noelaboration.

When esterification is complete, it is then sometimes necessary toadjust the final solvent-compound solution so as to produce a clearbright product. In a number of examples, either xylene-methanol wassatisfactory, or xylene alone was satisfactory. This is the caseparticularly in the instance of higher oxypropylations Where the productshowed comparatively limited water-solubility, although it sometimeshappened that even there it was desirable to mix in a semi-polar solventwith xylene, for example, to give a homogeneous system. Note, forexample, that xylene was reasonably satisfactory in Examples 13b through161), although even here there was some tendency towards turbidity andfor this reason it may have been better to have used the xylene-methanolmixture as was done in the preceding examples. In those examples wherethe mixed solvent was used approximately two-thirds of the solvent byweight was xylene and one-third by Weight was methanol. Xylene was usedfirst by itself. When all the water had been eliminated methanol equalto one-half the xylene or one-third the subsequent mixture, was added soas to give a single phase system. Other instances have been shown thatdiethyleneglycol diethylether is just as satisfactory, or moresatisfactory, than methanol, or a mixture of these two semi-polarsolvents can be used.

Another obvious procedure, of course, is merely to distill oil a solventsuch as xylene or xylene-methanol and then dissolve the product in asemi-polar solvent, such as methanol, ethanol, propanol, etc. It ispurely a matter of convenience to employ first a non-polar solvent(waterinsoluble to eliminate the Water during distillation) and then adda suitable polar solvent (hydrophile) to give a single-phase system.

Other procedures for eliminating the basic residual catalyst, if any,can be employed. For example, the oxyalkylation can be conducted inabsence of a solvent or the solvent removed after oxypropylation. Suchoxypropylation end product can then be acidified with just enoughconcentrated hydrochloric acid to just neutralize the residual basiccatalyst. To this product one can then add a small amount of anhydroussodium sulfate (suf"- cient in quantity to take up any water that ispresent) and then subject the mass to centrifugal force so as toeliminate the hydrated sodium sulfate and probably the sodium chlorideformed. The clear, somewhat viscous amber-to-dark-amber liquid soobtained may contain a small amount of sodium sulfate or sodium chloridebut, in any event, is perfectly acceptable for esterification in themanner previously described.

fit)

l TABLE 3 Max. Ex.No. I Amt. Esterlfiof Acid Solvent Solvent citinnEster l 1 (grams) l 'lemp.,

I C. l l J l 11') Xylene-Methanol. 248 i do 276 j 165 *Water ofhydration present in oxalic acid.

The procedure for manufacturing the esters has been illustrated bypreceding examples. If for any reason reaction does not take place in amanner that is acceptable, attention should be directed to the followingdetails: (a) Recheck the hydroxyl or acetyl value of the oxypropylatedderivative and use a stoichiometrically equivalent amount of acid; (b)if the reaction does not proceed with reasonable speed either raise thetempera ture indicated or else extend the period of time up to 12 or 16hours if need be; (c) if necessary, increase the amount of acidcatalyst; (d) if the esterification does not produce a clear product acheck should be made to see if an inorganic salt such as sodium chlorideor sodium sulfate is not precipitating out. Such salt should beeliminated, at least for exploration experimentation, and can be removedby filtering. Everything else being equal, as the size of the moleculeincreases and the reactive hydroxyl radical represents a smallerfraction of the entire molecule, more difiiculty is involved inobtaining complete esterification.

These acidic esters vary in color from amber to virtually a blacksolution, generally following close to the color of their parentoxypropylated derivative. Like the oxypropylated derivatives they aregenerally viscous and even tend to be somewhat more viscous than theparent compound. In fact, some of them verge on a state of beinggelatinous or rubbery, to which, as previously mentioned, theparatoluene sulfonic acid, or some similar acid, is added to preventcomplete gelation. Those esters made from the more watersoluble andsmaller molecular weight acids, i. e., oxalic and diglycolic, tend to berather water-dispersible whereas those made from acids such as phthalicor aconitic tend to be more oil-soluble, i. e., kerosene or xylene-TABLE 2 Ex. No. Amt. of Amt. of Ex. No. of of Hy- 90 Hy- Hydroxy Poly-Acidic droxy droxyl Oom- Polycarboxy Reactant earboxy Ester Oorn- Valuepound Reactant pound (grams) (grams) la 1, 924 320 150 Diglycolic Acid.114. 2 la 1, 924 320 150 Phthalic Anhydride... 126.5 la 1, 924 320 150Oxalic Acid 104. 1 1a 1, 924 320 150 Aconitic Acid. 153.0 241 2, 504 260150 Diglycolic Acid 93.0 211 2,504 260 150 Phthalic Anhydride 102. 9 2a2, 504 260 150 Oxalic Acid 84. 7 2a 2, 504 260 124. 1 3a 3, 150 196 70.5 3a 3,150 196 77. 9 3a 3,150 196 64. 2 3a 3, 150 196 94. 2 4a 4, 012142 50. 8 4a 4, 012 142 56. 2 4a 4, 012 142 46. 3 4a 4, 012 142 68. O

., repeated using an appropriately reduced ratio filtering chars, andthe like.

product. 7

terial the problem becomes increasingly more difiicult for 1.9 solublealthough still considerably hydrophile in character as is shown in thetables. in almost all cases it is necessary to use a semi-polar or polarsolvent, such as methanol, to take the esters into solution.

Even underthe most carefully controlled conditions of oxypropylationinvolving comparatively low temperature and long time of reaction thereare formed certain compounds whose compositions are still obscure. Suchside reaction products can contribute a substantial proportion of thefinal cogeneric reaction mixture. Various suggestions have been made asto the nature of these compounds, such as being cyclic polymers ofpropylene oxide, dehydration products with the appearance of a vinylradical, or isomers of propylene oxide -or derivatives thereof, i. e.,of an aldehyde, ketone, or

allyl alcohol. In some instances an attempt to react the stoichiometricamount of a polycarboxy acid with the oxypropylated derivative resultsin an excess of the carboxylated reactant for the reason that apparentlyunder conditions of reaction less reactive hydroxyl radicals are presentthan indicated by the hydroxyl value. Under such circumstances there issimply a residue of the carboxylic reactant which can be removed byfiltration or, if desired, the esterification procedure can be boxylicreactant.

Even the determination of the hydroxyl value and conventional procedureleaves much to be desired due either to the cogeneric materialspreviously referred to, or for that matter, the presence of anyinorganic salts or propylene oxide. Obviously this eliminated.

The solvent employed, if any, can be removed from the finished ester bydistillation and particularly vacuum distillation. pale amber to darkamber in color, and show moderate viscosity. They can be bleached withbleaching clays,

However, for the purpose of demulsification or the like color is not afactor and decolorization is not justified.

material prepared from an imidazoline. If one were concerned with amonohydroxylated material or a dihydroxylated material one 'might be'able to write a formula which in essence would represent the particularHowever, in a more highly hydroxylated mareasons which have already beenindicated in connection with oxypropylation and which can be examined bymerely considering for the moment a monohydroxylated material.

Oxyalkylation particularly in any procedure which involves theintroduction of repetitious ether linkages, i. e., excessiveoxyalkylation, using, for example, ethylene oxide, propylene oxide,etc., runs into difficulties of-at least two kinds; (a) formation of acogeneric mixture rather than a single compound, and (b) excessive sidereactions or the like. The former phase will be con sidered in theparagraphs following. As to the latter phase, see U. S. Patent No.2,236,919 dated April 1, 1941, to Reynhart.

Oxypropylation involves the same sort of variations as appears inpreparing high molal polypropylene glycols; Propylene glycol has asecondary alcoholic radical and Obviously then polypropylene glycols.could be obtained, at least theoretically, in'whicha primary alcoholradical.

two secondary alcoholic groups are united or a secondary alcohol groupis united to a primary alcohol group,-

etherization being involved, of course, in each instance:

Needless to say, the same situation applies when one' 7 hasoxypropylated polyhydric materials having 4 or more we T- 0fcompleteness of reaction.

hydroxyls, or the obvious equivalent.

of caroxide should be The final products or liquids are generallyUsually no eflort is made propylation taking place,

to differentiate between oxyfor example, at the primary alcohol radicalor the secondary alcohol radical. Actually, when such products areobtained, such as a-high a molal polypropylene glycol the manner hereindescribed or the products obtained in one does not obtain a singlederivative such as HO(RO)1tI-I or (RO)1LH in which n has one and onlyone value, for instance, 14, or 16,

or the like.

it) of closely related or touching homologues.

Rather, one obtains a cogeneric'mixture These materials invariably havehigh molecular weights and cannot be separated from one another by anyknown procedure without decomposition. The proportion of such mixturerepresents the contribution of the various individual 15 members of themixture.

On a statistical basis, of course,

It can be appropriately specified. For practical purposes one need onlyconsider the hydric alcohol because in oxypropylation of a monoessencethis is substantially formulas of a large number of compounds whichappear in some of the probable mixtures or can be prepared as componentsand mixtur conventionally.

Simply by way of illustration reference is made to U. S. Patent No.2,549,434, dated April 17,1951, to

es which are manufactured De Groote, Wirtel and Pettingill. 7

However, momentarily referring again to a monohydric initial reactant itis obvious that'if one selects any such simple hydroxylated compound andsubjects such'compropylation, it becomes app pound to oxyalkylation,such as oxyethylation, or oxyarent that one is really producing apolymer of the alkylene. oxides except for the terminal group. This isparticularly true where the amount of oxide added is stance, 10, 20, 30,40, or units.

comparatively large, for in- If such compound is subjected tooxyethylation so as to introduce 30 units of ethylene oxide, it is wellknown that one does not obtain a single constituent which, for the sakeof convenience, may be indicated as RO(C2H4O)30OH. In-

homologues, in which the 3 stead, one obtains a cogeneric mixture ofclosely related formula maybe shownas the following: RO(CzH4O)nH,wherein n, as'far as the statistical average goes, is 30, but theindividual members l where n has a value of 25, where 11 may represent35 present in significant amount may vary from instances and perhapsless, to a point or more. Such mixture is,

as stated, a cogeneric closely related series of touchinghomologouscompounds.

been made in regard to the 15 polymers.

Fundamental principles 0 Considerable investigation has distributioncurves for linear Attention is directed to the article entitled fcondensation polymerization, by Flory, which appeared in ChemicalReviews, volume 39, No. 1, page 137. 1

Unfortunately, as has been pointed out by Flory and other investigators,there is no satisfactorymethod, based on'either experimental ormathematical examination, of indicating the exact proportion of thevarious members 7 of touching homologous series which appear incogeneric condensation products of the kind described. This means (if;that from the practical standpoint, i; e., the ability to' 1. describehow to make the product under consideration and how to repeat suchproduction time after time without difliculty, it is necessary to resortto some other f method of description, or else consider the value of n,I in formulas such as those which have appeared previously and whichappear in the claims, as representinghoth individual constituents inwhich n has a single definite value, and also with the understandingthat n represents the average statistical valu e based on the assumptionThis may be illustrated as follows: Assume that in any particularexample the molal rotio of propylene oxide per hydroxyl is 15 to 1. In ageneric formula 15 to 1 could be 10, 20, or some other amount andindicated by n. Referring to this specific case actually one obtainsproducts in which :1 probably varies from 10 to 20, perhaps evenfurther. The average value, however, is 15, assuming, as previouslystated, that the reaction is complete. The product described by theformula is best described also in terms of method of manufacture.

The significant fact in regard to the oxyproyylated imidazoline productsherein described is that in their initial state of oxypropylation theyare substantially all water-soluble or water-dispersible. Asoxypropylation proceeds the oil solubility increases and thewater-solubility decreases. When one reaches, for instance, themolecular weight of 2000 to 3000 in the present case, for all practicalpurposes the compounds are oil-soluble, i. e., kerosene and, of course,xylene-soluble. However, in between if a sample of the product is shakenwith Water and allowed to stand varying percentages will not dissolve inwater. As the ratio of propylene oxide to imidazoline product increasesthe ratio of oil-solubility to water-solubility increases. I considersuch varying solubility factors to be all the more indicative of thefact that oxypropylation here produces cogeneric mixtures, some of whichare completely oil-soluble and some of which are still water-soluble.The exact composition is open to question for reasons which are commonto all oxyalkylations. It is interesting to note, however, that themolecular weights based on hydroxyl determination are almost alwaysconsiderably less than the molecular weight based on theoreticalconsideration.

It becomes obvious when carboxylic acidic esters are prepared from suchhigh molecular weight materials that the ultimate esterification productagain must be a cogeneric mixture. Likewise, it is obvious that thecontribution to the total molecular weight made by the polycarboxy acidis small. By the same token, one would expect the effectiveness of thedemulsifier to be comparable to the unesterified hydroxylated material.Remarkably enough, in practically every instance the product isdistinctly better, and in the majority much more effective.

PART 5 Conventional demulsifying agents employed in the treatment of oilfield emulsions are used as such, or after dilution with any suitablesolvent, such as water, petroleum hydrocarbons, such as benzene,toluene, xylene, tar acid oil, cresol, anthracene oil, etc. Alcohols,particularly aliphatic alcohols, such as methyl alcohol, ethyl alcohol,denatured alcohol, propylalcohol, butyl alcohol, hexyl alcohol, octylalcohol, etc., may be employed as diluents. Miscellaneous solvents suchas pine oil, carbon tetrachloride, sulfur dioxide extract obtained inthe refining of petroleum, etc., may be employed as diluents. Similarly,the material or materials employed as the demulsifying agent of myprocess may be admixed with one or more of the solvents customarily usedin connection with conventional demulsifying agents. Moreover, saidmaterial or materials may be used alone or in admixture with othersuitable well-known classes of demulsifying agents.

It is well known that conventional demulsifying agents may be used in awater-soluble form, or in an oil-soluble form, or in a form exhibitingboth oiland watersolubility. Sometimes they may be used in a form whichexhibits relatively limited oil-solubility. However, since such reagentsare frequently used in a ratio of 1 to 10,000 or 1 to 20,000, or i to30,000, or even 1 to 40,000, or 1 to 50,000 as in desalting practice,such an apparent insolubility in oil and water is not significantbecause said reagents undoubtedly have solubility within suchconcentrations. This same fact is true in regard Ill) to the material ormaterials employed as the demulsifying agent of my process.

In practicing the present process, the treating or demulsifying agent isused in the conventional way, well known to the art, described, forexample, in Patent 2,626,929, dated January 27, 1953, Part 3, andreference is made thereto for a description of conventional proceduresof demulsifying, including batch, continuous, and down-the-holedemulsification, the process essentially involving introducing a smallamount of demulsifier into a large amount of emulsion with adequateadmixture with or without the application of heat, and allowing themixture to stratify.

As noted above, the products herein described may be used not only indiluted form, but also may be used admixed with some other chemicaldemulsifier. A mixture which illustrates such combination is thefollowing:

Oxyalkylated derivative, for example, the product of Example 2b, 20%;

A cyclohexylamine salt of a polypropylated naphthalene m-onosulfonicacid, 24%;

An ammonium salt of a polypropylated naphthalene monosulfonic acid, 24%;

A sodium salt of oil-soluble mahogany petroleum sulfonic acid, 12%:

A high-boiling aromatic Isopropyl alcohol, 5%.

The above proportions are all weight percents.

Having thus described my invention, what I claim as new and desire tosecure by Letters Patent, is:

I. A process for breaking petroleum emulsions of the water-in-oil typecharacterized by subjecting the emulsion to the action of a dcmulsifierincluding hydrophile synthetic products; said hydrophile syntheticproducts being obtained by reaction between (A) a polycarboxy acid, and(B) a highly oxypropylated substituted ring compound petroleum solvent,15%;

selected from the group consisting of Y R-C R C R RC R R-C R i it new inin which R is a divalent alkylene radical selected from the classconsisting of and in which D represents a divalent, non-amino, organicradical containing less than 25 carbon atoms, composed of elements fromthe group consisting of C, H, O, and N; Y represents a divalent, organicradical containing less than 25 carbon atoms, composed of elements fromthe group consisting of C, H, O, and N, and containing at least oneamino group; R is a member of the class consisting of hydrogen,aliphatic hydrocarbon radicals, hydroxylated aliphatic hydrocarbonradicals, cycloaliphatic hydrocarbon radicals, and hydroxylatedcycloaliphatic hydrocarbon radicals; R is a member of the classconsisting of hydrogen, aliphatic radicals and cycloaliphatic radicals,with the proviso that in the occurrence of the radicals R and R" therebe present at least one group of 8 to 32 uninterrupted carbon atoms; andwith the further proviso that (1) there be introduced at least 12 molesof propylene oxide per substituted nitrogen-containing ring compound,and that (2) there be employed at least one mole of the polycarboxyreactant for each reactive hydroxyl radical.

2. A process for breakingpetroleum emulsions of the Water-in-oilttypecharacterized by subjecting the emulsion to the action of a demulsifierincluding synthetic hydrophile products; said synthetic hydrophileproducts being obtained by reaction between (A) a polycarboxy acid, and(B) a highly oxypropylated substituted imidazoline selected from thegroup consisting of in which D represents a divalent, non-amino, organicradical containing less than 25 carbon atoms, composed of elements fromthe group consisting of C, H, O, and N; Y represents a divalent, organicradical containing less than 25 carbon atoms, composed of elements fromthe group consisting of C, H, O, and N, and containing at least oneamino group; R is a member of the class consisting of hydrogen,aliphatic hydrocarbon radicals, hydroxylated aliphatic hydrocarbonradicals, cycloaliphatic hydrocarbon radicals, and hydroxylatedcycloaliphatic hydrocarbon radicals; R is a member of the classconsisting of hydrogen, aliphatic radicals and cycloaliphatic radicals,with the proviso that in the occurrences of the radicals R and R" therebe present at least one group of 8 to 32 uninterrupted carbon atoms; andwith the further proviso that (1) there be introduced at least 12 molesof propylene oxide per substituted imidazoline molecule and that (2)there be employed at least one mole of the polycarboxy I;

reactant for each reactive hydroxyl radical.

3. A process for breaking petroleum emulsions of the water-in-oil typecharacterized by subjecting the emulsion to the action of a demulsifierincluding synthetic hydrophile products, said synthetic hydrophileproducts being obtained by reaction between (A) a dicarboxy acid, and

(B) a highly oxypropylated substituted imidazoline selected from thegroup consisting of NCH2 N-CEz N-CHz N-CHz RC R-C 'li-C R-G lT -CH2 vN-CH2 NCH2 N-CH2 H JR!!! DIR/I 3T1}!!! in which D represents a divalent,non-amino, organic 1 radical containing less than 25 carbon atoms,composed of elements from the group consisting of C, H, O, and N; Yrepresents a divalent, organic radical containing less than 25 carbonatoms, composed of elements from the group consisting of C, H, O, and N,and containing at I least one amino group; R is a member of the classconsisting of hydrogen, aliphatic hydrocarbon radicals, hydroxylatedaliphatic hydrocarbon radicals, cycloaliphatic hydrocarbon radicals, andhydroxylated cycloaliphatic hydrocarbon radicals; R is a member of theclass consisting of hydrogen aliphatic radicals and cycloaliphaticradicals, with the proviso that in the occurrences of the radicals R andR there be present at least one group of 8 to 32 uninterrupted carbonatoms; and with the further in which Y represents a divalent, organicradical containing less than 25 carbon atoms, composed of elements fromthe group consisting of C, H, O, and N, and containing at least oneamino group; R is a member of the class consisting of hydrogen,aliphatic hydrocarbon radicals, hydroxylated aliphatic hydrocarbonradicals, cycloaliphatic'hydrocarbon radicals, and hydroxylatedcycloaliphatic hydrocarbon radicals; R" is a member of the classconsisting of hydrogen, aliphatic radicals and cycloaliphatic radicals,with the proviso that in the occurrences of the radicals it and R therebe present at least one group of 8 to 32 uninterrupted carbon atoms; andwith the further proviso that (1) there be introduced at least 12 molesof propylene oxide per substituted imidazoline molecule, and that (2)there be employed at least one mole ofthe dicarboxy reactant for eachreactive hydroxyl radical.

5. A process for breaking petroleum emulsions of the V Water-in-oil typecharacterized by subjecting the emulsion proviso that (1) there beintroduced at least 12 moles of propylene oxide per substitutedimidazoline molecule and a that (2) there be employed at least one moleof the dicar boxy reactant for each reactive hydroxyl radical.

4. A process for breaking petroleum emulsions of the water-inoil typecharacterized by subjecting the emulsion to the action of a dcmulsifierincluding synthetic hydrophile products, said synthetic hydropbileproducts being obtained by reaction between (A) a dicarboxy acid, and(B) a highly oxypropylated substituted imidazoline consisting of to theaction of a demulsifier including synthetic hydrophile products, saidsynthetic hydrophile products being obtained by reaction between (A) adicarboxy acid, and (B) a highly oxypropylated substituted imidazolineconsisting of N-CH2 R-C\ N-CHz in which Y represents a divalent, organicradical containing less than 25 carbon atoms, composed of elements fromthe group consisting of C, H, O, and N, and containing at least oneamino group, R is a member of the class consisting of hydrogen,aliphatic hydrocarbon radicals, hydroxylated aliphatic hydrocarbonradicals, cycloaliphatic hydrocarbon radicals, and hydroxylatedcycloaliphatic hydrocarbon radicals; R is a member of the classconsisting of hydrogen, aliphatic radicals and cycloaliphatic radicals,With the proviso that in the occurrences ot the radicals R and R" therebe present at least one group of 8 to 32 uninterrupted carbon atoms; andwith the further proviso that (1) there be introduced at least 12molecules of propylene oxide per substituted imidazoline molecule; that(2) there be present a multiplicity of labile hydrogen atoms in thesubstituted irnidazoline molecule; and that (3) there be employed atleast one mole of thedicarboxy reactant for each reactive hydroxylradical.

6. A process for breaking petroleum emulsions of the water-in-oil typecharacterized by subjecting the emulsion to the action of a demulsifierincluding synthetic hydrophile products, said synthetic hydrophileproducts being obtained by reaction between (A) a dicarboxy acid, and(B) a highly oxypropylated substituted imidazoline consisting of N-CH2 Y'R/I in which Y represents a divalent organic radical contain- 7 ingless than 25 carbon atoms, composed of elements from the groupconsisting of C, H, O, and N, and containing at least one amino group; Ris a member of the class consisting of hydrogen, aliphatic hydrocarbonradicals, hydroxylated aliphatic hydrocarbon radicals, cycloaliphatichydrocarbon radicals, and hydroxylated cycloaliphatic hydrocarbonradicals; R"'is a member of the class consisting of hydrogen, aliphaticradicals and cycloaliphatic radicals, with the proviso that in theoccurrences of the radicals R and R there be present at least one groupof 8 to 32 uninterrupted carbon atoms; and with the further proviso that(1) there be introduced at least 12 molecules of propylene oxide persubstituted imidazoline molecule; that (2) there be present amultiplicity of labile hydrogen atoms in the substituted imidazolinemolecule; that (3) there be employed at least one mole of the dicarboxyreactant for each reactive hydroxyl radical; and that (4) there bepresent in the substituted imidazoline radical a plurality of hydroxylradicals.

7. A process for breaking petroleum emulsions of the water-in-oil typecharacterized by subjecting the emulsion to the action of a demulsifierincluding synthetic hydrophile products, said synthetic hydrophileproducts being obtained by reaction between (A) a dicarboxy acid, and(B) a highly oxypropylated substituted imidazoline consisting of inwhich Y represents a divalent organic radical containing less than 25carbon atoms, composed of elements from the group consisting of C, H, O,and N, and containing at least one amino group; R is a member of theclass consisting of hydrogen, aliphatic hydrocarbon radicals,hydroxylated aliphatic hydrocarbon radicals, cycloaliphatic hydrocarbonradicals, and hydroxylated cycloali phatic hydrocarbon radicals; R" is amember of the class consisting of hydrogen, aliphatic radicals andcycloaliphatic radicals, with the proviso that in the occurrences of theradicals R and R" there be present at least one group of 8 to 32uninterrupted carbon atoms; and with the further proviso that (1) therebe introduced at least 12 molecules of propylene oxide per substitutedimidazoline molecule; that (2) there be present a multiplicity of labilehydrogen atoms in the substituted imidazoline molecule; that (3) therebe employed at least one mole of the dicarboxy reactant for eachreactive hydroxyl radical; that (4) said oxypropylated substitutedimidazoline prior to esterification be oil-soluble; and that (5) therebe present in the substituted imidazoline radical a plurality ofhydroxyl radicals.

8. The process of claim 7 wherein the radical Y is derived from apolyethylene amine containing at least 3 nitrogen atoms, and the amountof propylene oxide employed is in excess of 14 and not over 60 moleculesof propylene oxide per substituted imidazoline molecule.

9. The process of claim 7 wherein the radical Y is de rived from apolyethylene amine containing at least 3 nitrogen atoms, and the amountof propylene oxide employed is in excess of 14 and not over 60 moleculesof propylene oxide per substituted imidazoline molecule, and

with the proviso that the dicarboxy acid is diglycolic acid.

10. The process of claim 7 wherein the radical Y is derived from apolyethylene amine containing at least 3 nitrogen atoms, and the amountof propylene oxide employed is in excess of 14 and not over molecules ofpropylene oxide per substituted imidazoline molecule; with the provisothat the dicarboxy acid is diglycolic acid, and with the further provisothat the radical R attached directly to the 2-carbon atom is derivedfrom ricinoleic acid.

11. The process of claim 7 wherein the radical Y is derived from apolyethylene amine containing at least 3 nitrogen atoms, and the amountof propylene oxide employed is in excess of 14 and not over 60 moleculesof propylene oxide per substituted imidazoline molecule;

with the proviso that the dicarboxy acid is diglycolic acid, and withthe further proviso that the radical R attached directly to the 2-carbonatom is derived from oleic acid.

12. The process of claim 7 wherein the radical Y is derived frompolyethylene amine containing at least 3 nitrogen atoms, and the amountof propylene oxide employed is in excess of 14 and not over 60 moleculesof propylene oxide per substituted imidazoline molecule; with theproviso that the dicarboxy acid is diglycolic acid, and with the furtherproviso that the radical R attached directly to the 2-carbon atom isderived from abietic acid.

13. The process of claim 7 wherein the radical Y is derived from apolyethylene amine containing at least 3 nitrogen atoms, and the amountof propylene oxide employed is in excess of 14 and not over 60 moleculesof propylene oxide per substituted imidazoline molecule;.

with the proviso that the dicarboxy acid is diglycolic acid, and withthe further proviso that the radical R attached directly to the 2-carbonatom is derived from tall oil.

14. The process of claim 7 wherein the radical Y is derived from apolyethylene amine containing at least 3 nitrogen atoms, and the amountof propylene oxide employed is in excess of 14 and not over 60 moleculesof propylene oxide per substituted imidazoline molecule; with theproviso that the dicarboxy acid is diglycolic acid, and with the furtherproviso that the radical R attached directly to the 2-carbon atom isderived from linseed oil fatty acids.

References Cited in the file of this patent UNITED STATES PATENTS

1. A PROCESS FOR BREAKING PETROLEUM EMULSIONS OF THE WATER-IN-OIL TYPECHARACTERIZED BY SUBJECTING THE EMULSION TO THE ACTION OF A DEMULSIFIERINCLUDING HYDROPHILE SYNTHETIC PRODUCTS; SAID HYDROPHILE SYNETHETICPRODUCTS BEING OBTAINED BY REACTION BETWEEN (A) A POLYCARBOXY ACID, AND(B) A HIGHLY OXYPROPYLATED SUBSTITUTED RING COMPOUND SELECTED FROM THEGROUP CONSISTING OF